NO, I am not having problems with vista, both Vista machines are running 12.5.1 fine, one with an old dongle and one with a brand new dongle, though I don't know the differences between the two in terms of HASP 4 or HASP HL.
I don't think this is a dongle issue with the XP machine, though I am very surprised and dissapointed with the lack of information regarding install/upgrades and the use of dongles having jsut spent so much on new 12.5.1 licences. There is very little useful and clear information on this anywhere.